Shocking Information: Electrical Safety Concerns at Live Events

by Jeff Cech, General Manager

THS-DangerHVWe’re in the process of building out an additional “Green Kit”—the smaller of the 2 sizes of adapter/tool kits we send to every job we crew. One of the most used and most important tools in the kit is the multimeter.

Managing AC power is at the foundation of almost everything we do as a live sound company. Advancing details for temporary power, determining voltage/amperage specifications, working with power distros and disconnects on show-site, and metering power are everyday occurrences.

Naturally, our foremost consideration is safety of the crew, the venue, and our equipment.

As I started looking for a new meter for the kit, I was reminded of an article from a past issue of PLASA Protocol that described the investigation into a fire and the death of an electrician who was metering power at the switchegear in a commercial building. Tragically, the electrician was using a meter that was not appropriately rated for the task, which resulted in an enormous arc flash.

Standards for voltage meters were established by the IEC with an eye towards rating devices for arc flash (or incident energy) potential. The standard is a four-category (Cat. I-IV) rating system. The closer you are to the power source, the higher the category—and the greater the danger. Here is an article from Fluke’s site about the ratings.

We use Cat. III meters, which we feel are appropriate for metering power at the meter points of our power distros and related branch circuits.

Another article on the Fluke site is a good reminder about safety tips for metering power.  One important point of the article is to verify you are using the appropriate PPE (personal protective equipment) for the task at hand—including using the appropriate category of meter.

Working around electricity is inherently dangerous, yet essential to live events. Being armed with information and the correct tools (especially correct category of meter) is the important first step towards a safe show.

Let TC Furlong safely support your next live event.  Contact one of our project managers at 847.367.9588.